ext4_page_crypto-doesnt-need-ctx

   1 ext4 crypto: ext4_page_crypto() doesn't need a encryption context
   2
   3 Since ext4_page_crypto() doesn't need an encryption context (at least
   4 not any more), this allows us to simplify a number function signature
   5 and also allows us to avoid needing to allocate a context in
   6 ext4_block_write_begin().  It also means we no longer need a separate
   7 ext4_decrypt_one() function.
   8
   9 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  10 ---
  11  fs/ext4/crypto.c   | 28 +++++-----------------------
  12  fs/ext4/ext4.h     |  3 +--
  13  fs/ext4/inode.c    |  4 ++--
  14  fs/ext4/readpage.c |  2 +-
  15  4 files changed, 9 insertions(+), 28 deletions(-)
  16
  17 diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
  18 index 4573155..3a5a7a2 100644
  19 --- a/fs/ext4/crypto.c
  20 +++ b/fs/ext4/crypto.c
  21 @@ -253,8 +253,7 @@ typedef enum {
  22         EXT4_ENCRYPT,
  23  } ext4_direction_t;
  24
  25 -static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
  26 -                           struct inode *inode,
  27 +static int ext4_page_crypto(struct inode *inode,
  28                             ext4_direction_t rw,
  29                             pgoff_t index,
  30                             struct page *src_page,
  31 @@ -353,7 +352,7 @@ struct page *ext4_encrypt(struct inode *inode,
  32         if (IS_ERR(ciphertext_page))
  33                 goto errout;
  34         ctx->w.control_page = plaintext_page;
  35 -       err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, plaintext_page->index,
  36 +       err = ext4_page_crypto(inode, EXT4_ENCRYPT, plaintext_page->index,
  37                                plaintext_page, ciphertext_page);
  38         if (err) {
  39                 ciphertext_page = ERR_PTR(err);
  40 @@ -378,31 +377,14 @@ struct page *ext4_encrypt(struct inode *inode,
  41   *
  42   * Return: Zero on success, non-zero otherwise.
  43   */
  44 -int ext4_decrypt(struct ext4_crypto_ctx *ctx, struct page *page)
  45 +int ext4_decrypt(struct page *page)
  46  {
  47         BUG_ON(!PageLocked(page));
  48
  49 -       return ext4_page_crypto(ctx, page->mapping->host,
  50 +       return ext4_page_crypto(page->mapping->host,
  51                                 EXT4_DECRYPT, page->index, page, page);
  52  }
  53
  54 -/*
  55 - * Convenience function which takes care of allocating and
  56 - * deallocating the encryption context
  57 - */
  58 -int ext4_decrypt_one(struct inode *inode, struct page *page)
  59 -{
  60 -       int ret;
  61 -
  62 -       struct ext4_crypto_ctx *ctx = ext4_get_crypto_ctx(inode);
  63 -
  64 -       if (IS_ERR(ctx))
  65 -               return PTR_ERR(ctx);
  66 -       ret = ext4_decrypt(ctx, page);
  67 -       ext4_release_crypto_ctx(ctx);
  68 -       return ret;
  69 -}
  70 -
  71  int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
  72  {
  73         struct ext4_crypto_ctx  *ctx;
  74 @@ -426,7 +408,7 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
  75         }
  76
  77         while (len--) {
  78 -               err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, lblk,
  79 +               err = ext4_page_crypto(inode, EXT4_ENCRYPT, lblk,
  80                                        ZERO_PAGE(0), ciphertext_page);
  81                 if (err)
  82                         goto errout;
  83 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  84 index 766b7f7..3f248c9 100644
  85 --- a/fs/ext4/ext4.h
  86 +++ b/fs/ext4/ext4.h
  87 @@ -2063,8 +2063,7 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx);
  88  void ext4_restore_control_page(struct page *data_page);
  89  struct page *ext4_encrypt(struct inode *inode,
  90                           struct page *plaintext_page);
  91 -int ext4_decrypt(struct ext4_crypto_ctx *ctx, struct page *page);
  92 -int ext4_decrypt_one(struct inode *inode, struct page *page);
  93 +int ext4_decrypt(struct page *page);
  94  int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex);
  95
  96  #ifdef CONFIG_EXT4_FS_ENCRYPTION
  97 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  98 index 612fbcf..ac2f0cf 100644
  99 --- a/fs/ext4/inode.c
 100 +++ b/fs/ext4/inode.c
 101 @@ -965,7 +965,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 102         if (unlikely(err))
 103                 page_zero_new_buffers(page, from, to);
 104         else if (decrypt)
 105 -               err = ext4_decrypt_one(inode, page);
 106 +               err = ext4_decrypt(page);
 107         return err;
 108  }
 109  #endif
 110 @@ -3393,7 +3393,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
 111                         /* We expect the key to be set. */
 112                         BUG_ON(!ext4_has_encryption_key(inode));
 113                         BUG_ON(blocksize != PAGE_CACHE_SIZE);
 114 -                       WARN_ON_ONCE(ext4_decrypt_one(inode, page));
 115 +                       WARN_ON_ONCE(ext4_decrypt(page));
 116                 }
 117         }
 118         if (ext4_should_journal_data(inode)) {
 119 diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
 120 index e26803f..a91e4bf 100644
 121 --- a/fs/ext4/readpage.c
 122 +++ b/fs/ext4/readpage.c
 123 @@ -62,7 +62,7 @@ static void completion_pages(struct work_struct *work)
 124         bio_for_each_segment_all(bv, bio, i) {
 125                 struct page *page = bv->bv_page;
 126
 127 -               int ret = ext4_decrypt(ctx, page);
 128 +               int ret = ext4_decrypt(page);
 129                 if (ret) {
 130                         WARN_ON_ONCE(1);
 131                         SetPageError(page);